Intel Xeon E5 2680 v2 's Advantages
Released 3 years and 6 months late
Newer PCIe version (3 vs 2)
Higher base frequency (2.8GHz vs 2.4GHz)
Larger L3 cache size (25MB vs 12MB)
More modern manufacturing process (22nm vs 32nm)
Intel Xeon E5620 's Advantages
Lower TDP (80W vs 115W)